1. Field of the Invention
This invention relates generally to air handling equipment, and particularly to a device for removal of grease from the exhaust fumes from a kitchen exhaust hood.
2. Description of the Prior Art
Various devices have been designed and manufactured for removal of fumes from a kitchen. A common type is a canopy hood situated above a cooking appliance or appliances and which is connected through an exhaust duct to a roof-mounted blower which pulls air from the hood and discharges it above the roof. Such units typically have sets of removable baffle-type grease filters mounted in the hood itself and which can be removed periodically from the hood and washed in a sink or otherwise to remove accumulated grease from them. It is well known that such filters do not remove all of the grease. The result is that the grease which passes through such filters accumulates in the ductwork from the hood to the roof-mounted blower. It also accumulates in the blower itself and associated components. Eventually some accumulated grease from the blower or blower-mounting curb runs down onto the roof of the building. This creates an unsightly appearance, to say nothing of the potential fire hazard from grease which has accumulated in the duct above the filters.
Various arrangements have been proposed for removing grease from the fumes entering a kitchen exhaust hood. One approach is a water wash canopy hood. An example is shown in U.S. Pat. No. 4,753,218 issued Jun. 28, 1988 to Gary J. Potter. That patent identifies many prior art patents, some of which disclose various water wash hood systems. The patent also identifies manufacturers of various systems. The Potter patent emphasizes a cone shaped spray of cold water and detergent solution inside the hood itself and through which fumes are to pass. Water recirculation is also specified. Some water wash systems are custom made for the particular kitchen or combination of kitchen equipment items to be handled. They tend to be large and expensive.
There are many conventional hoods which cannot be used satisfactorily with charbroilers. Too much grease gets through them into ductwork, rooftop blowers and out into the air. There is no convenient way to adapt them to handling the fumes generated by charbroilers. U.S. Pat. No. 4,323,373 issued Apr. 6, 1982 to Frederick F. Fritz discloses a filter box mounted on top of a canopy hood to remove grease from the exhaust air. It proposes continuous wash down of Dacron fiber filters by a cold water/detergent solution. There remains a need for a better system which can be used with conventional hoods already in place but employed as a retrofit item between the hood and the exhaust ductwork, for removing from the exhaust fumes, the grease which passes the conventional baffle-type grease filters in the hood. The present invention addresses that need.